Smoke alarm with offset detection chamber and shield

Abstract

A smoke alarm includes a housing having a generally hollow interior, a printed circuit board arranged within the interior of the housing, and an optical chamber assembly connected to the printed circuit board. The optical chamber assembly has an interior chamber and at least one smoke entry location. A substantial entirety of the interior chamber is external to the housing. At least one light device for evaluating particles is arranged within an interior chamber of the optical chamber assembly.

What is claimed is: 
     
       1. A smoke alarm comprising:
 a housing including an upper housing portion and a lower housing portion, the upper housing portion and the lower housing portion, in combination, define a generally hollow interior of the housing; 
 a printed circuit board arranged within the interior of the housing; 
 an optical chamber assembly connected to the printed circuit board, the optical chamber assembly including an optical cover having an interior chamber and at least one smoke entry location, the optical cover protruding beyond an exterior surface of the lower housing portion such that a substantial entirety of the interior chamber of the optical cover is external to the housing; and 
 at least one light device for evaluating particles within the interior chamber of the optical cover. 
 
     
     
       2. The smoke alarm of  claim 1 , wherein the at least one smoke entry location is a single smoke entry location. 
     
     
       3. The smoke alarm of  claim 2 , wherein the single smoke entry location being formed about a periphery of the optical cover. 
     
     
       4. The smoke alarm of  claim 1 , wherein the optical cover further comprises an end piece and a plurality of side members extending from the end piece, wherein a portion of the plurality of side members arranged external to the housing forms the single smoke entry location. 
     
     
       5. The smoke alarm of  claim 1 , wherein the at least one light device is mounted external to the internal chamber. 
     
     
       6. The smoke alarm of  claim 1 , further comprising a shield having a body, the body being offset from the housing, wherein the shield is mounted in overlapping arrangement with the smoke entry location. 
     
     
       7. The smoke alarm of  claim 6 , wherein at least one dimension of the body is larger than a corresponding dimension of the optical cover. 
     
     
       8. The smoke alarm of  claim 6 , wherein the body is curved about a first axis, the first axis extending substantially perpendicular to an axis extending through the optical chamber assembly and the optical cover. 
     
     
       9. The smoke alarm of  claim 8 , wherein the body is curved about a second axis, the second axis extending substantially perpendicular to the first axis. 
     
     
       10. The smoke alarm of  claim 6 , wherein the shield further comprises a plurality of supports extending from the body and connected to the housing, wherein a configuration of the plurality of supports is selected to minimize interference with a flow toward the smoke entry location. 
     
     
       11. The smoke alarm of  claim 1 , wherein a groove is formed in a surface of the housing facing an area to be monitored. 
     
     
       12. The smoke alarm of  claim 1 , wherein the housing has a substantially solid sidewall.